A. Field of Invention
The invention is directed to the field of manufacturing processes relevant to the production of high strength articles such as any article having a structural component including vehicle frames generally and bicycle frames specifically, and to articles produced by such processes, and composite bicycle forks and other components. In the preferred embodiment the invention is directed to a method for manufacturing a composite bicycle frame such as a filament wound bicycle frame, the related bicycle frame, and related bicycle components including a composite bicycle fork.
B. The Background Art
In the prior art, various bicycle frames and frame components were known, including those described in U.S. Pat. No. 4,923,203 in the name of Trimble et al., U.S. Pat. No. 5,213,322 in the name of Enders, U.S. Pat. No. 4,067,589 in the name of Hon, U.S. Pat. No. 5,011,172 in the name of Bellanca et al., U.S. Pat. No. 4,550,927 in the name of Resele, U.S. Pat. No. 4,548,422 in the name of Michel et al., U.S. Pat. No. 3,533,643 in the name of Yamada, U.S. Pat. No. 5,016,895 in the name of Hollingsworth, U.S. Pat. No. 4,923,203 in the name of Hollingsworth, and U.S. Pat. No. 4,565,383 in the name of Isaac, each of which is hereby incorporated by reference in its entirety for the material disclosed therein. Foreign patents containing pertinent disclosure include Italian Patent No. 448,310 in the name of F. Janecek, French Patent No. 895,046 in the name of Delorge et al., and U.K. Patent No. 19,193 in the name of Otto Schonauer, each of which is hereby incorporated by reference in its entirety for the material disclosed therein.
In the prior art it was known that traditional bicycle frames could be constructed from metal tubing that was round in cross section. Referring to FIG. 1, it can be seen that such traditional round tubing frames typically consisted of two main triangle shapes 101 and 102. The larger of these two triangle shapes 101, referred to herein as the front triangle 101, consisted of a seat tube 103, a top tube 104 and a down tube 105 which were welded or adhesively joined to appropriate lugs (such as head lug 106 and bottom bracket lug 107). In the prior art, it should be noted that the bicycle frame could be constructed by laying up composite pre-preg into a female mold to produce a monocoque frame. Two smaller triangle shapes 102 were employed, referred to herein as the rear triangles 102. Each consisted of a seat stay 108, a chain stay 109 and a seat tube 103 which was shared with the front triangle. The rear triangle assembly 102, when viewed from the side, appeared to be a single triangle, but when viewed from the top or rear, actually was two spaced apart rear triangles each terminating at its rear in an axle drop-out 110 for mounting of a rear bicycle wheel.
In the prior art it was known that filament wound tubing could be constructed and that articles could be made therefrom. In the prior art if it was desired to manufacture a bicycle frame using filament wound tubing typically individual tubing members which were round in cross section would be constructed and then joined to aluminum cast lugs and more recently to composite lugs. Composite tubing used in conventional tube and lug frames to date has largely been produced using carbon/epoxy or graphite/epoxy pre-preg and roll wrapping process. Alternatively, in the prior art a hollow bicycle frame could be made from square tubing using a lay-up, braiding process. The reader's attention is directed to U.S. Pat. No. 5,215,322 and to U.S. Pat. No. 4,923,203 for general prior art disclosure. It was also known in the prior art that bicycle frames or portions thereof could be made by injection molding. For general reference the reader is directed to U.S. Pat. Nos. 5,011,172 and 4,067,589.
The prior art does not reveal, however, how to manufacture a bicycle frame by a filament winding process so that the resulting frame is light weight, strong, attractive, and cost efficient to manufacture. Nor does the prior art disclose a composite bicycle fork with the structure and characteristics of the invented fork. The invented frame meets these needs by providing a frame useful for road bicycles, mountain bicycles, tandem bicycles, and other wheeled vehicles.